Horizontal boring machines are used more and more frequently to install or replace utility services. The machines include a surface mounted boring unit which has a rotation motor to rotate a drill string having a drill bit at the end thereof and a thrust motor to thrust the drill string forward in the bore hole. The machine can also be used to backream a hole previously bored to enlarge the hole and pull in the new service.
Many horizontal boring machines require the operator to manually and individually adjust the rotation torque and thrust force which together define the amount of power applied to the downhole boring tool. Maintaining the correct balance of power between these two functions is necessary to maximize the efficiency of the unit. Inexperienced operators find it difficult to keep an efficient balance of thrust and rotation. Although necessary for both the boring of the pilot bore and backreaming to enlarge the size of the bore hole, the need for finite control is usually greater when backreaming. Therefore, a need exists for an apparatus to provide for operation of the machine at optimum efficiency even when used by inexperienced operators.